Ethylene and propylene are important building blocks for the petrochemical industry. These olefins are used in the manufacturing of polymers such as polyethylene, polypropylene, polystyrene and many more chemicals of commercial interest. Over 90% of global olefin production may come from the high temperature steam cracking of naphtha or ethane and propane. The steam cracking process, which utilizes furnaces, is highly energy intensive, and 1.5 to 2 tons of carbon dioxide are produced for every ton of olefin product.
Natural gas production from shale deposits has dramatically increased supply in recent years. As a result of the continued global demand for olefins and the potential for a new growing supply of ethane and propane available in natural gas liquids from shale deposits, interest has risen around expanding the capacity of ethylene and propylene derived from these new sources. However, there are many challenges associated with the processes for deriving ethylene and propylene from natural gas. For example, cracking ethane and propane is highly endothermic, requiring significant amounts of energy to facilitate the production of olefins. As stated in Ullmann's Encyclopedia of Industrial Chemistry, as the alkane chain length increases, the heat of formation approaches 1800 kJ/kg. Ethylene, 13 ULLMANN'S ENCYCLOPEDIA OF INDUSTRIAL CHEMISTRY 465, 476 (Viley-VCH Verlag GmbH & Co. KGaA, 2012). Thus, “[e]thane, the most refractory alkane besides methane, has the most endothermic heat of cracking, +4893 kJ/kg.” Id. In addition, olefin production from natural gas liquids is often limited by several over-oxidation pathways.
Additionally, technology has not yet advanced to enable cheap transportation of natural gas to many global regions. Accordingly, although natural gas production from shale deposits has dramatically increased in a few select regions, the petrochemical industry in other regions of the world relies heavily on the production of ethylene and propylene from naphtha.
Accordingly, there is a long standing need for improved systems and methods for efficiently producing olefins from hydrocarbon feeds, such as hydrocarbon feeds including naphtha.